Tales abound of the heroic pianists of old, who beat pianos into submission, and broke strings without even raising a forearm. Young Georgian pianist Khatia Buniatishvili clearly wants to join that company. True, I didn’t actually see any keys flying or hear any strings snap. But by the end of the Three Dances from Stravinsky’s Petrouchka, one or two notes had acquired that worrying out-of-tune rasp that shows a piano is wilting under the strain.

Buniatishvili’s blistering power went hand-in-hand with an astonishing steely-wristed technique, which was a boon in the Stravinsky, and in the mad dance of Ravel’s La Valse, and in Chopin’s B flat minor Scherzo. Under her hands these pieces took on a crazed, tumultuous quality. At the opposite pole was the spectral calm of Le Gibet, Ravel’s evocation of a corpse swinging from a gallows. I’ve never heard this piece played with such a threadbare sound, and at such a slow pace. In between came three Intermezzi by Brahms, which were so quiet and thin in sound it seemed as if they’d died and returned as ghosts.

This was all very striking. But where was the musical sense in it all? When everything is pushed to extremes, all we’re left with is a series of shocks to the nervous system, which very soon wear off. I never thought the beginning of Chopin’s heroic and tragic Scherzo could sound trivial, but Buniatishvili somehow managed it. The piece began fast and then accelerated, skidding to a halt at the first cadence with cartoonish suddenness.

Buniatishvili’s problem is that she gets intoxicated by her own virtuosity, and musical judgment goes out of the window. This isn’t to say an effect of intoxication isn’t appropriate at times. In fact in Ravel’s La Valse a sense of encroaching delirium is the essence of the piece. But we have to feel delirium pushing against a firm underlying waltz tempo, and in Buniatishvili’s performance that dance pulse barely registered. It was crazed from the start.

All this exaggeration was sorely disappointing, because here and there moments of real sensitivity emerged. The delicacy of the very first piece, Ravel’s Ondine, promised something special. In Brahms’s deeply nostalgic B flat minor Intermezzo her sound took on a lovely entangled, cobwebby quality, clear and hazy all at once. But to really savour these little nuances one needs a basic trust in the performer. That, I’d long since lost.